Narrow band incoherent optical carrier generator
AssigneeGeneral Instrument Corporation
InventorDavid R. Huber
Life of this patent
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Abstract
A narrow bandwidth incoherent optical source is provided. A superluminescent source includes a gain medium having an input end and an output end. The input end of the gain medium is optically coupled to a reflector to cause spontaneous emissions within a predetermined band exiting the input of the gain medium to be reflected back into the medium. Spontaneous emissions outside of the predetermined band are lost. The gain medium can comprise a doped fiber, such as an Erbium doped fiber. An optical isolator prevents the superluminescent source from lasing. By providing a plurality of reflectors operating in different bands, the superluminescent source can generate a plurality of optical carriers.
Claims21
A narrow band incoherent optical carrier generator for use in optical communication systems comprising:
- a superluminescent source operating below lasing threshold including a gain medium for generating incoherent spontaneous emission and having an input end and an output end;
- selective reflector means for reflecting energy within a predetermined narrow band;
- and
- input coupler means for optically coupling the input end of said gain medium to said selective reflector means to cause spontaneous emissions within said predetermined band exiting the input of said gain medium to be reflected back into said gain medium, without reflecting spontaneous emissions outside of said predetermined band back into said medium, thereby producing a narrow band incoherent optical carrier generator.
A method for communicating signals over an optical fiber communication path comprising the steps of:
- generating an incoherent optical carrier signal in a superluminescent source;
- limiting said carrier signal to a narrow bandwidth;
- amplifying said limited bandwidth carrier signal within said source;
- and
- modulating said amplified carrier signal with an information signal for communication over said optical fiber communication path.
An optical source comprising:
- a rare earth doped optical fiber having an input end and an output end;
- means for pumping said doped fiber to cause spontaneous emission therein without exceeding lasing threshold for output from said output end;
- selective reflector means for reflecting light over a limited bandwidth encompassing a desired wavelength of said spontaneous emission;
- and
- means for optically coupling the input end of said doped fiber to said selective reflector means to reflect spontaneous emissions within said limited bandwidth exiting the input end of said doped fiber back into said doped fiber for output from said output end, without reflecting light outside of said bandwidth back into said doped fiber, thereby producing a limited bandwidth optical source.
Dependencies are inferred from the claim text.